A system may utilize a combination of real-time and polling connectors for data crawling. A real-time connector may use a collector to write data associated with a new event from a database to a channel and record external identifiers (IDs) associated the data. A polling connector may use a verifier to compare the recorded IDs with IDs associated with a batch of data, and may write any data of the batch of data to the channel that has not been written previously written by the collector. The system may include an onboarder for reading data previously stored in the database.